为了使车辆在规定的距离内停车,必须安装()装置 ["牵引","ATO","制动","缓解"]
在TCR识别抗原的信号转导过程中起关键作用的CD分子是() ["CD2","CD3","CD4","CD8","CD28"]
下列农药中,能够防治芹菜软腐病的是()。 ["农用链霉素","甲基托布津","代森锰锌","甲基立枯磷"]
流式细胞仪可用于下述哪种标本的粘附因子的检测() ["组织切片","内皮细胞","血清","分泌物","其他体液"]
指出胸腔积液X线表现叙述错误者() ["胸腔积液区为透过度增加区","胸腔积液为均匀透过度减低区","积液面不超过第四前肋为少量积液","液面超过第四前肋,但未超过第二前肋为中量","液面在第二前肋之上为大量"]
为什么生产过程中气体需要多级压缩?